/* Shared responsive layer: header, navigation, footer.
   Section-specific breakpoints live next to their sections in home.css and claude.css. */

@media (min-width: 1600px) {
  :root {
    --container: 1320px;
  }
}

/* Collapse navigation */
@media (max-width: 1100px) {
  /* Without JS the nav stays visible as a scrollable row under the brand. */
  html:not(.js) .site-header {
    position: relative;
    height: auto;
  }

  html:not(.js) .site-header__inner {
    flex-wrap: wrap;
    padding-block: 0.75rem;
  }

  html:not(.js) .site-nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
  }

  html:not(.js) .hero {
    margin-top: 0;
  }

  .js .nav-toggle {
    display: inline-block;
  }

  .js .site-nav {
    position: fixed;
    inset: var(--header-h) 0 0 0;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: var(--space-6);
    padding: var(--space-5) var(--gutter) var(--space-6);
    overflow-y: auto;
    background:
      radial-gradient(70% 40% at 100% 0%, rgba(90, 169, 255, 0.12), transparent 70%),
      var(--c-bg);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility 0s linear var(--dur);
  }

  .js .site-header.is-open .site-nav {
    visibility: visible;
    opacity: 1;
    transform: none;
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility 0s;
  }

  /* A backdrop-filter on the header would become the containing block of the fixed menu panel. */
  .js .site-header.is-open {
    background: var(--c-bg);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  .js .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .js .site-nav__list li {
    border-bottom: 1px solid var(--c-line);
  }

  .js .site-nav__list a {
    display: flex;
    align-items: baseline;
    gap: 1rem;
    min-height: 64px;
    padding: 0.6rem 0;
    font-size: clamp(1.75rem, 1.2rem + 3vw, 2.5rem);
    font-weight: 700;
    letter-spacing: 0.02em;
    color: var(--c-text);
  }

  .js .site-nav__list a::after {
    display: none;
  }

  .js .site-nav__list a:hover,
  .js .site-nav__list a.is-active,
  .js .site-nav__list a[aria-current="page"] {
    color: var(--c-accent-strong);
  }

  .js .site-nav__num {
    display: inline;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    color: var(--c-text-3);
  }

  .js .site-nav__meta {
    display: grid;
    gap: 0.4rem;
    font-size: var(--fs-sm);
    color: var(--c-text-2);
  }

  .js .site-nav__meta p:first-child {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    color: var(--c-teal);
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    letter-spacing: 0.12em;
    text-transform: uppercase;
  }

  .js body.nav-open {
    overflow: hidden;
  }
}

@media (max-width: 960px) {
  .site-footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 720px) {
  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }
}

@media (max-width: 480px) {
  .header-cta {
    display: none;
  }

  .btn-row .btn {
    width: 100%;
  }
}

@media (max-width: 360px) {
  .brand__by {
    display: none;
  }
}